Meaning

If marriage was recited by force or coercion, such marriage is invalid in Islam.

Wassalam.

If he did it wrongly then rectified his mistake and did it correctly, his Salah will be valid.

Wassalam.

If such act was committed unintentionally, then you should do your best to clarify to the people and make them aware if the truth. We must repair the damage which we caused even unintentionally.

Wassalam.

Predestination is everything in life which is out of our will or control like our creation, our birth place,v our family,our skin color, or height, our eyes color , our body functioning etc. every predestined matter is never part of our our responsibility. Our faith and deeds are our responsibility and every one with be questioned about his faith and deeds. Allah (ASWT) Says in Quran :And stop them, verily they will be questioned. Sura Saffar, verse 24.

Sura 65:3 says that everything created by Allah has a discipline and order. It never says that our deeds are destined or I forced in us. Allah Says in Quran ( We Have guided him ( human being) the way, and he decides to be grateful of disgraceful) Sura Al-Insaan, verse 3.

Wassalam.

قُلْ هُوَ اللَّهُ أَحَدٌ

اللَّهُ الصَّمَدُ

لَمْ يَلِدْ وَلَمْ يُولَدْ

وَلَمْ يَكُن لَّهُ كُفُوًا أَحَدٌ

Translation: Say, “He is Allah , [who is] One, Allah , the Eternal Refuge [As-Samad], He neither begets (gives birth to) nor is born, Nor is there to Him any equivalent.” [Surah Ikhlas]

The tafseer of this great surah, Surah Ikhlas is very, very extensive; volumes of books have been written on it. One of our writers, Abdul-Ahad, may Allah bless him and increase him in his nearness to Allah, has written very extensively about this surah. Therefore, I will suggest to you some great readings about this great surah, and instead, break down the Arabic grammar word by word.

Tafseer of Surah Ikhlas

Grammatical Analysis

• Qul (قُلْ): Say. It is a command (fi’l amr), both to the Prophet (salallahu alayhi wa sallam), in response to the question of the mushrikeen “tell us the lineage of your Lord,” and to us. There are four surahs that begin with qul–surah Ikhlas, Surah Naas, Surah Falaq, Surah Kafiroon. (We completed tafseer of all these surahs already, walhamdulillah.)
• Huwa (هُوَ): He, or it. One of the most common words you’ll come across. It’s technically third-person, singular, and masculine. In this case, it refers to Allah.
• Allah (اللَّهُ): This word is called laf dhuw jalaala (the honorable name) when we refer to it. Because it’s not proper to say “Allah is mansoob (having fatha on the last letter)” or “Allah is marfoo’ (having damma on the last letter)” when we speak about grammar.
• Ahad (أَحَدٌ): Ahad means “one.” Then again, wahid also means one; the difference is that, if I said I have wahid books, it means I have one book. Or two books. Or more books–“I have one book.” On the other hand, if I said I have ahad books … that means I have one and only one book. Not two. Not three. Just one. So here, he is Allah, Al-Ahad–the one, the unique (perhaps unique is a better translation of ahad).
• As-Samad (الصَّمَدُ): This is one of the names of Allah. It means the one who everybody depends on, but the one who doesn’t depend on anyone. Like if there was a fund-raiser and there’s only one person in the community who has the money, and he pays it–he can be described as samad. Allah is AS-Samad, THE samad, who we all depend on.
• Lam (لَمْ): Lam is a particle of negation similar to laa or maa or other negations. Lam makes mudaari’ (present/future-tense) verbs majzoom (having sukoon on the last letter).
• Yalid (يَلِدْ): Yalidu is mudaari’ (present/future-tense), singular, and masculine. It’s from the verb walada, which means to give birth to. It’s majzoom (yalid and not yalidu) because of lam.
• Wa (وَ): Wa by itself, means “and.”
• Yuwlad (يُولَدْ): This is the passive form of yalid (evidenced by the damma and fatha on the first and second letters). So “yalidu” means “he gives birth to,” and yuwladu means “he was given birth to.” It’s also majzoom, with sukoon, because of lam (it’s connected by the wa, which carries over the grammatical case, too).
• Yakun (يَكُن): Yakunu is the mudaari’ of kaana (he was). It means “he is.” Again, it’s majzoom because of lam.
• Lahu (لَّهُ): Lahu is the preposition “li” (for), and hu is the majroor version of huwa. So li + huwa = lahu, roughly translated as “for him.”
• Kufuwan (كُفُوًا): If you look in the fiqh books about the chapter of orphan girls, they must be married to someone of the same “kufwan,” someone of the same level and status and rank as she is. So here, it’s saying that there’s nobody at the same level as Allah–because he is Al-Ahad.

Wassalam

We never believe that all the companions left Islam after the passing away of the Prophet Muhammad (SAWA). We believe in Quranic facts (Sura 3, verse 144) stating :(Muhammad is really a messenger before him messengers were sent, if he dies or is killed, you will then turn back on your heels).  Most of Muslims of that society remained as Muslims in faith but did not obey the orders of the Prophet (SAWA) who clearly ordered them to follow and obey Ali when he announced seventy days before his departure that ( Foe whom so ever I am the master, Ali is his master).

IRTADDU ارتدّوا does not mean that they left Islam, but did not fulfill their responsibility to obey the Prophetic orders in following the divine leadership which was been appointed by Allah and the Prophet.

Wassalam.

1. This verse (6:159) means something completely different from what seems from your question. شيعا means different groups following different leaders, which is totally different from the word Shi’a which means the followers of the Prophets and their real successors.

2. Shi’a in Arabic language means the followers, who can be followers of true leader, so they are the real believers, or can be following a wrong leader, then they will be mislead.

3. Allah (SWT) Has Granted the title Shi’a to His best servants as you can read in Sura Al-Saffaat after mentioning the Prophet Noah, the mention of Prophet Ebrahim ( And Ebrahim was from his Shi’a) (وإنَّ مِن شِيعَتِهِ لَإبراهيم. 
4. Allah (SWT) mentioned in Sura Al-Qassass about Prophet Musa and his followers and his enemies. He called the followers of Musa as his Shi’a and the opposite people as his enemies. Al-Qassass, verse 15.

'5. Shi'a is a title granted by Allah, The Glorious, to the sincere followers of the Prophets.

6. Shi'a Muslims are the real followers of the Prophet Muhammad (SAWA) through following his Progeny Ahlul Bayt (AS) which was been ordered by Allah and the Prophet (SAWA).

7. The Prophet Muhammad (SAWA) has repeatedly called the most sincere believers as "Shi'a of Ali" as you can read in many Sunni books of Hadeeth like

1. Shawaahid Al-Tanzeel by Al-Haakim Al-Hasakaani , V. 2,  P. 356. 
2. Kufa Ayat Al-Talib by Al-Kanji Al-Shafi'ee, P.244.

3. Al-Manaaqib by Al-Khawarizmi Al-Hanafi , P. 62.

4. Al-Fosoul Al-Muhimmah by Ibn Al-Sabbagh Al-Maliki , P. 126

5. Ibn Asaakir in Tareekh Dimishq 2:442.

6. Al-Khateeb Al-Baghdadi in Tareekh Baghdad, V.12, P. 289.

7. Al-Tabarani in Al-Mo'jam Al-Waseet, V. 6, P. 354.

'Wassalam.

Greeting in Islam is one of the teachings in Quran and authentic Hadeeths. Those who submit to the Will of Allah and believe fully in Islam, use the greeting which has been mentioned in Quran and Hadeeth. Those who use other greetings are been blamed in Quran (And when they come to you,v they greet you with a greeting which Allah never greeted you with) Sura 58, Verse 8.

Allah Says in Quran : (When you enter the house, then greet one another with the greeting from Allah, blessed and nice.) Sura 24, verse 61.

'Muslim should greet Muslims with the greeting of Allah which is Salam and never use the greetings of non Muslims when greetings Muslims.

It is narrated that a person greeted the Prophet Muhammad (SAWA) by saying : Good morning عِمتَ صباحا. The Prophet replied him: Allah Has replaced it with better greeting; Salaam.

'Wassalam.

Our existence  has been created by Allah, The Creator of all creatures. Creatures are never part of The Creator. We exist by His help and Mercy and can never live without His help and Mercy. That can never mean that we are part of Him. Allah Says in Quran : Nothing is like Allah ليس كمثله شيء.

Wassalam.

Chaining up of the devils in the month of Ramadan is mentioned in narrations in both Sunni and Shia books which means that devils will not be free to mislead people as they usually do in other months, that is why the numbers of worshiping Muslims ( fasting, praying and giving charity etc)   are much more in this month of Ramadan compared with other months. Chaining up the devils does not mean that no sin will be committed during the month of Ramadan, but it means that decreasing and restricting their influence on many Muslims.

'Wassalam.